Wilms tumor (WT), a pediatric nephroblastoma that occurs with a frequency of 1 in 10,000 births, has been the subject of intense clinical and basic research for several years. The tumor is embryonic in origin; it is detected in children usually during the first 5 years of life and can occur unilaterally or bilaterally. A WT arises when condensed metanephric mesenchymal cells of the developing kidney fail to properly differentiate. The implication of the Wilms tumor 1 (WT1) tumor suppressor gene in the etiology of WT illustrated the impact that genetic alterations can have on both development and tumorigenesis.
Wilms tumor protein I (WT1) is a zinc finger transcription factor expressed during normal ontogenesis such as in fetal kidney, testis and ovary. In adults, WT1 expression is limited to low levels on hematopoietic stem cells, myoepithelial progenitor cells, renal podocytes and some cells in testis and ovary. Recent demonstration that WT1 is over expressed in several types of leukemia suggested that WT1 would be an attractive target for immunotherapy for various cancers.